And if only they upheld [the law of] the Torah, the Gospel, and what has been revealed to them from their Lord, they would have consumed [provision] from above them and from beneath their feet.
Who is the Lord mentioned in this verse?
رب in the Quran is used almost exclusively to refer to Allah.
وإن الله ربي وربكم فاعبدوه هذا صراط مستقيم
[Jesus said], "And indeed, Allah is my Lord and your Lord, so worship Him. That is a straight path."
إن ربكم الله الذي خلق السماوات والأرض في ستة أيام ثم استوى على العرش يدبر الأمر ما من شفيع إلا من بعد إذنه ذلكم الله ربكم فاعبدوه أفلا تذكرون
Indeed, your Lord is Allah, who created the heavens and the earth in six days and then established Himself above the Throne, arranging the matter [of His creation]. There is no intercessor except after His permission. That is Allah, your Lord, so worship Him. Then will you not remember?
In this ayah Lord means Allah(الله, swt) which is the Arabic word for God.