The word(s) "therefor" appears 71 time(s) in 70 verse(s) in Quran in Abdullah Yusuf Ali translation.

(11) So the king said: "Bring him unto me; I will take him specially to serve about my own person." therefore when he had spoken to him, he said: "Be assured this day, thou art, before our own presence, with rank firmly established, and fidelity fully proved!

(12) Now when they saw no hope of his (yielding), they held a conference in private. The leader among them said: "Know ye not that your father did take an oath from you in Allah's name, and how, before this, ye did fail in your duty with Joseph? therefore will I not leave this land until my father permits me, or Allah commands me; and He is the best to command.

(13) therefore, by the Lord, We will, of a surety, call them to account,

(14) therefore expound openly what thou art commanded, and turn away from those who join false gods with Allah.

(15) Those who do wish for the (things of) the Hereafter, and strive therefor with all due striving, and have Faith,- they are the ones whose striving is acceptable (to Allah).

(16) (Some) say they were three, the dog being the fourth among them; (others) say they were five, the dog being the sixth,- doubtfully guessing at the unknown; (yet others) say they were seven, the dog being the eighth. Say thou: "My Lord knoweth best their number; It is but few that know their (real case)." Enter not, therefore, into controversies concerning them, except on a matter that is clear, nor consult any of them about (the affair of) the Sleepers.

(17) He said: "(The power) in which my Lord has established me is better (than tribute): Help me therefore with strength (and labour): I will erect a strong barrier between you and them:

(18) Verily Allah is my Lord and your Lord: Him therefore serve ye: this is a Way that is straight.

(19) "Verily I am thy Lord! therefore (in My presence) put off thy shoes: thou art in the sacred valley Tuwa.

(20) "therefore let not such as believe not therein but follow their own lusts, divert thee therefrom, lest thou perish!"..