The word(s) "sad" appears 29 time(s) in 28 verse(s) in Quran in Mohsin Khan translation.

(21) Verily, the Muslims (those who submit to Allah in Islam) men and women, the believers men and women (who believe in Islamic Monotheism), the men and the women who are obedient (to Allah), the men and women who are truthful (in their speech and deeds), the men and the women who are patient (in performing all the duties which Allah has ordered and in abstaining from all that Allah has forbidden), the men and the women who are humble (before their Lord - Allah), the men and the women who give sadaqat (i.e. Zakat, and alms), the men and the women who observe Saum (fast) (the obligatory fasting during the month of Ramadan, and the optional Nawafil fasting), the men and the women who guard their chastity (from illegal sexual acts) and the men and the women who remember Allah much with their hearts and tongues Allah has prepared for them forgiveness and a great reward (i.e. Paradise).

(22) sad. [These letters (sad, etc.) are one of the miracles of the Qur'an, and none but Allah (Alone) knows their meanings]. By the Qur'an full of reminding (explanations and honour for the one who believes in it).

(23) And indeed, We did try Sulaiman (Solomon) and We placed on his throne Jasad (a devil, so he lost his kingdom for a while) and he did return (to Allah with obedience and in repentance, and to his throne and kingdom by the Grace of Allah).

(24) Verily, those who give sadaqat (i.e. Zakat and alms), men and women, and lend Allah a goodly loan, it shall be increased manifold (to their credit), and theirs shall be an honourable good reward (i.e. Paradise).

(25) And spend (in charity) of that with which We have provided you before death comes to one of you, and he says: "My Lord! If only You would give me respite for a little while (i.e. return to the worldly life), then I should give sadaqah (i.e. Zakat ) of my wealth, and be among the righteous [i.e. perform Hajj (pilgrimage to Makkah) and other good deeds].

(26) But when they will see it (the torment on the Day of Resurrection) approaching, the faces of those who disbelieve will change and turn black with sadness and in grief and it will be said (to them): "This is (the promise) which you were calling for!"

(27) And some faces, that Day, will be Basirah (dark, gloomy, frowning, and sad),

(28) In her neck is a twisted rope of Masad (palm fibre).