The word(s) "locks" appears 6 time(s) in 5 verse(s) in Quran in Muhammad Pickthal translation.

(1) And We made the son of Mary and his mother a portent, and We gave them refuge on a height, a place of flocks and watersprings.

(2) And when he came unto the water of Midian he found there a whole tribe of men, watering. And he found apart from them two women keeping back (their flocks). He said: What aileth you? The two said: We cannot give (our flocks) to drink till the shepherds return from the water; and our father is a very old man.

(3) Will they then not meditate on the Qur'an, or are there locks on the hearts?

(4) The guilty will be known by their marks, and will be taken by the forelocks and the feet.

(5) And when thou seest them their figures please thee; and if they speak thou givest ear unto their speech. (They are) as though they were blocks of wood in striped cloaks. They deem every shout to be against them. They are the enemy, so beware of them. Allah confound them! How they are perverted!