The word(s) "seal" appears 18 time(s) in 18 verse(s) in Quran in Muhammad Habib Shakir translation.

(1) Allah has set a seal upon their hearts and upon their hearing and there is a covering over their eyes, and there is a great punishment for them.

(2) Therefore, for their breaking their covenant and their disbelief in the communications of Allah and their killing the prophets wrongfully and their saying: Our hearts are covered; nay! Allah set a seal upon them owing to their unbelief, so they shall not believe except a few.

(3) Say: Have you considered that if Allah takes away your hearing and your sight and sets a seal on your hearts, who is the god besides Allah that can bring it to you? See how We repeat the communications, yet they turn away.

(4) Is it not clear to those who inherit the earth after its (former) residents that if We please We would afflict them on account of their faults and set a seal on their hearts so they would not hear.

(5) These towns-- We relate to you some of their stories, and certainly their apostles came to them with clear arguments, but they would not believe in what they rejected at first; thus does Allah set a seal over the hearts of the unbelievers

(6) They preferred to be with those who remained behind, and a seal is set on their hearts so they do not understand.

(7) The way (to blame) is only against those who ask permission of you though they are rich; they have chosen to be with those who remained behind, and Allah has set a seal upon their hearts so they do not know.

(8) Then did We raise up after him apostles to their people, so they came to them with clear arguments, but they would not believe in what they had rejected before; thus it is that We set seals upon the hearts of those who exceed the limits.

(9) These are they on whose hearts and their hearing and their eyes Allah has set a seal, and these are the heedless ones.

(10) Thus does Allah set a seal on the hearts of those who do not know.