The word(s) "seal" appears 17 time(s) in 17 verse(s) in Quran in Saheeh International translation.

(1) Allah has set a seal upon their hearts and upon their hearing, and over their vision is a veil. And for them is a great punishment.

(2) And [We cursed them] for their breaking of the covenant and their disbelief in the signs of Allah and their killing of the prophets without right and their saying, "Our hearts are wrapped". Rather, Allah has sealed them because of their disbelief, so they believe not, except for a few.

(3) Say, "Have you considered: if Allah should take away your hearing and your sight and set a seal upon your hearts, which deity other than Allah could bring them [back] to you?" Look how we diversify the verses; then they [still] turn away.

(4) Has it not become clear to those who inherited the earth after its [previous] people that if We willed, We could afflict them for their sins? But We seal over their hearts so they do not hear.

(5) Those cities - We relate to you, [O Muhammad], some of their news. And certainly did their messengers come to them with clear proofs, but they were not to believe in that which they had denied before. Thus does Allah seal over the hearts of the disbelievers.

(6) They were satisfied to be with those who stay behind, and their hearts were sealed over, so they do not understand.

(7) The cause [for blame] is only upon those who ask permission of you while they are rich. They are satisfied to be with those who stay behind, and Allah has sealed over their hearts, so they do not know.

(8) Then We sent after him messengers to their peoples, and they came to them with clear proofs. But they were not to believe in that which they had denied before. Thus We seal over the hearts of the transgressors

(9) Those are the ones over whose hearts and hearing and vision Allah has sealed, and it is those who are the heedless.

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