The word(s) "foundation" appears 9 time(s) in 8 verse(s) in Quran in Abdullah Yusuf Ali translation.

(1) And remember Abraham and Isma'il raised the foundations of the House (With this prayer): "Our Lord! Accept (this service) from us: For Thou art the All-Hearing, the All-knowing.

(2) He it is Who has sent down to thee the Book: In it are verses basic or fundamental (of established meaning); they are the foundation of the Book: others are allegorical. But those in whose hearts is perversity follow the part thereof that is allegorical, seeking discord, and searching for its hidden meanings, but no one knows its hidden meanings except Allah. And those who are firmly grounded in knowledge say: "We believe in the Book; the whole of it is from our Lord:" and none will grasp the Message except men of understanding.

(3) Never stand thou forth therein. There is a mosque whose foundation was laid from the first day on piety; it is more worthy of the standing forth (for prayer) therein. In it are men who love to be purified; and Allah loveth those who make themselves pure.

(4) Which then is best? - he that layeth his foundation on piety to Allah and His good pleasure? - or he that layeth his foundation on an undermined sand-cliff ready to crumble to pieces? and it doth crumble to pieces with him, into the fire of Hell. And Allah guideth not people that do wrong.

(5) The foundation of those who so build is never free from suspicion and shakiness in their hearts, until their hearts are cut to pieces. And Allah is All-Knowing, Wise.

(6) Those before them did also plot (against Allah's Way): but Allah took their structures from their foundations, and the roof fell down on them from above; and the Wrath seized them from directions they did not perceive.

(7) So his fruits (and enjoyment) were encompassed (with ruin), and he remained twisting and turning his hands over what he had spent on his property, which had (now) tumbled to pieces to its very foundations, and he could only say, "Woe is me! Would I had never ascribed partners to my Lord and Cherisher!"

(8) Wealth and sons are allurements of the life of this world: But the things that endure, good deeds, are best in the sight of thy Lord, as rewards, and best as (the foundation for) hopes.