The Meaning of Cheerfulness
Bashashah linguistically: is being bright-faced. Bashahtu bihi, abashshu, bashashatan. A man who is hashshun bashshun, meaning: bright-faced and kind.  al-Sihah, al-Jawhari (1/44).
Bashashah technically: is being bright-faced with happiness, smiles, approachability, and gentleness in matters.  al-Targhib wa al-Tarhib, al-Mundhari (1/73). The Difference between Cheerfulness, Pleasantness (Hashashah), and Gladness (Bishr)  al-Furuq al-Lughawiyyah, al-`Askari (p. 101).
Cheerfulness: is showing happiness with whom one meets, whether they are the first or last. Gladness: is the first happiness that manifests upon meeting. Pleasantness: is lightness for the sake of good. It comes from: a thing that is hashsh, if it is easy to accept. If a man is easily giving, it is said: he is hashsh, clear in his hashashah.Praise of Cheerfulness and Being Bright-faced in the Qur’an and Sunnah
❖ Allah, exalted, says: “On that Day there will be radiant faces, looking towards their Lord.” al-Qiyamah: 22, 23.
❖ He, exalted, also says: “On that Day some faces will be beaming, laughing and rejoicing.” `Abasa: 38, 39.
❖ Abu Dharr, Allah be pleased with him, said: “The Prophet ﷺ told me: ‘Do not belittle anything from doing good, even if it be that you meet your brother with a bright face.’”  Reported by Muslim (2626).
❖ Abu Dharr, Allah be pleased with him, said: “The Prophet ﷺ said: ‘Smiling in the face of your brother is charity for you.’”  Reported by al-Tirmdhi (1956) and this is his wording, and Ibn Hibban (529). al-Tirmidhi said: “It is sound but strange.” al-Albani authenticated it in Sahih Sunan al-Tirmidhi (1956). Quotes from the Predecessors about Cheerfulness and Being Bright-faced
❖ Mu`adh ibn Jabal, Allah be pleased with him, said: “If two Muslim men meet one another, and each smiles in the face of the other then takes his hand, their sins fall just as tree leaves fall from a tree.”  Reported by Ibn Abi al-Dunya in al-Ikhwan (114).
❖ It is narrated by `Abdullah al-Mubarak that he described good morals, saying: “It is being bright-faced, expending good, and preventing harm.”  Reported by al-Tirmidhi (2005).
❖ It was said to al-Awza`i, Allah have mercy upon him: “What is it to honour your guest?” He said: “Being bright-faced, and having good speech.”  Ihya’ `Ulum al-Din, al-Ghazali (2/18). Benefits of Cheerfulness and Being Bright-faced
Being bright-faced gives glad-tidings, causing others to accept their bringer. A stern face drives people away. Being bright-faced is part of noble character when treating people. Being bright-faced is a sign for what is in the soul. It is rare that you find a cheerful, pleasant person but that he has a pure, good soul. The love of Allah, honourable and majestic. Barriers to Acquiring Cheerfulness
An impure soul, wherein all forms of evil attributes boil, like envy, rancour, and malice. Not following the guidance of the Prophet ﷺ who encouraged this characteristic with his words and action. Hating people, and disliking that any good reaches them. Not appreciating the reward that follows from having this characteristic. Means to Acquiring Cheerfulness
Reflecting over and appreciating the reward which the Law has outlined for having a bright-face and pleasantly meeting Muslims. Following the guidance of the Prophet ﷺ, whose character was cheerfulness, and he taught it to his Ummah with his statements and action ﷺ. Having love for the people allows you to be bright-faced with them. Purifying oneself from evil characteristics like envy and malice which makes one hate those around him and dislike that good comes to them, giving one a stern, unpleasant face. Habitually smiling, practicing this as a normal characteristic for the self. Examples of Cheerfulness from the Life of the Prophet ﷺ and the Predecessors
❖ His cheerfulness with Khadijah’s sister, Allah be pleased with her, as a form of loyalty to her. This is narrated by `A’ishah, Allah be pleased with her, when she said: “Halah the daughter of Khuwaylid, the sister of Khadijah, sought permission to enter upon Allah’s Messenger ﷺ, so he recognised it from that of Khadijah, and so he found rest due to this and said: “Allah, it is Halah...”  Reported by al-Bukhari but hung (3821), and Muslim reported it connected (2437).
❖ In the biography of Shihab al-Din Yahya ibn Isma`il ibn Muhammad ibn `Abdillah ibn Muhammad al-Qaysarani, it is found that he used to seek the love of the righteous, excessively fast and worship, have patience over harm, yet not treat comrades and enemies but with goodness and a bright face.  Shadharat al-Dhahab, Ibn `Imad (6/175).
❖ Ishaq ibn Yahya ibn Ishaq ibn Ibrahim used to have good character, influencing those around him, being himself cheerful and inciting cheerfulness in others. He was easy-going in his pursuits, not showing animosity, distinguished by justice, and shy of not being so.  A`yan al-`Asr wa A`wan al-Nasr, al-Safadi (1/137). Adages, Proverbs, and Poetry about Cheerfulness and Being Bright-faced
❖ Ibn Hibban said: “Cheerfulness is the adornment of scholars and the nature of the wise. Bringing glad-tidings puts out the fire of stubbornness, and burns the energy of animosity. In it is a shield from the aggressor, and freedom from those looking to beg. Whoever is bright-faced to the people, they will necessarily have that which he gives them to give back.”  Rawdat al-`Uqala’, Ibn Hibban (1/75).
❖ al-Ahnaf said: “The head of decency is cheerfulness and being affectionate to the people.”  Al-tadhkirah al-Hamduniyyah, Ibn Hamdun (1/204).
❖ Ibn Abi al-Dunya said: “Abu `Abdillah Muhammad ibn Khalaf al-Taymi narrated that Sa`id ibn `Ubayd al-Ta’i used to mention proverbially:
“Protect yourself from people with cheer,
All of them, and meet them with a bright face.
Leave off a confused, stern face with people,
For a stern face is the head of stupidity.
Every time you wish to take an enemy, you take
A friend as an enemy, despite valuing comradery.”  al-Ishraf fi Manazil al-Ashraf, Ibn Abi al-Dunya (1/225).