The word(s) "slow" appears 4 time(s) in 4 verse(s) in Quran in Abdullah Yusuf Ali translation.

(1) Or that He may not call them to account by a process of slow wastage - for thy Lord is indeed full of kindness and mercy.

(2) Those who reject Faith say: "Why is not the Qur'an revealed to him all at once? Thus (is it revealed), that We may strengthen thy heart thereby, and We have rehearsed it to thee in slow, well-arranged stages, gradually.

(3) Then, when We decreed (Solomon's) death, nothing showed them his death except a little worm of the earth, which kept (slowly) gnawing away at his staff: so when he fell down, the Jinns saw plainly that if they had known the unseen, they would not have tarried in the humiliating Penalty (of their Task).

(4) Or a little more; and recite the Qur'an in slow, measured rhythmic tones.