The word(s) "sound" appears 23 time(s) in 22 verse(s) in Quran in Saheeh International translation.

(1) Or do you intend to ask your Messenger as Moses was asked before? And whoever exchanges faith for disbelief has certainly strayed from the soundness of the way.

(2) And test the orphans [in their abilities] until they reach marriageable age. Then if you perceive in them sound judgement, release their property to them. And do not consume it excessively and quickly, [anticipating] that they will grow up. And whoever, [when acting as guardian], is self-sufficient should refrain [from taking a fee]; and whoever is poor - let him take according to what is acceptable. Then when you release their property to them, bring witnesses upon them. And sufficient is Allah as Accountant.

(3) And Allah had already taken a covenant from the Children of Israel, and We delegated from among them twelve leaders. And Allah said, "I am with you. If you establish prayer and give zakah and believe in My messengers and support them and loan Allah a goodly loan, I will surely remove from you your misdeeds and admit you to gardens beneath which rivers flow. But whoever of you disbelieves after that has certainly strayed from the soundness of the way."

(4) Say, "Shall I inform you of [what is] worse than that as penalty from Allah? [It is that of] those whom Allah has cursed and with whom He became angry and made of them apes and pigs and slaves of Taghut. Those are worse in position and further astray from the sound way."

(5) Say, "O People of the Scripture, do not exceed limits in your religion beyond the truth and do not follow the inclinations of a people who had gone astray before and misled many and have strayed from the soundness of the way."

(6) And the people of Moses made, after [his departure], from their ornaments a calf - an image having a lowing sound. Did they not see that it could neither speak to them nor guide them to a way? They took it [for worship], and they were wrongdoers.

(7) And say, "My Lord, cause me to enter a sound entrance and to exit a sound exit and grant me from Yourself a supporting authority."

(8) Moses said to him, "May I follow you on [the condition] that you teach me from what you have been taught of sound judgement?"

(9) [Zechariah] said, "My Lord, make for me a sign." He said, "Your sign is that you will not speak to the people for three nights, [being] sound."

(10) And how many have We destroyed before them of generations? Do you perceive of them anyone or hear from them a sound?