The word(s) "reason" appears 4 time(s) in 4 verse(s) in Quran in Muhammad Pickthal translation.

(1) Or like a rainstorm from the sky, wherein is darkness, thunder and the flash of lightning. They thrust their fingers in their ears by reason of the thunder-claps, for fear of death, Allah encompasseth the disbelievers (in His guidance, His omniscience and His omnipotence).

(2) Prove orphans till they reach the marriageable age; then, if ye find them of sound judgment, deliver over unto them their fortune; and devour it not by squandering and in haste lest they should grow up Whoso (of the guardians) is rich, let him abstain generously (from taking of the property of orphans); and whoso is poor let him take thereof in reason (for his guardianship). And when ye deliver up their fortune unto orphans, have (the transaction) witnessed in their presence. Allah sufficeth as a Reckoner.

(3) Call unto the way of thy Lord with wisdom and fair exhortation, and reason with them in the better way. Lo! thy Lord is Best Aware of him who strayeth from His way, and He is Best Aware of those who go aright.

(4) But if thou turn away from them, seeking mercy from thy Lord, for which thou hopest, then speak unto them a reasonable word.