Allah's Favors upon Them Allah reminds of His tremendous favors upon the Children of Israel and His numerous blessings. He saved them from their enemy, Fir`awn, and He relieved their eyes by drowning him and his hosts all at one time while they watched. Allah said,
(And We drowned Fir`awn people while you were looking.) 2:50 Al-Bukhari recorded that Ibn `Abbas said, "When the Messenger of Allah ﷺ came to Al-Madinah, he found the Jews fasting the day of `Ashura'. Therefore he asked them about it and they said, `This is the day that Allah gave Musa victory over Fir`awn.' Then, the Prophet said,
وَوَاعَدْنَاكُمْ جَانِبَ الطُّورِ الْأَيْمَنَ (And appointed for you the right side of the mount Tur. (20:80) ) After their deliverance from the threat of the Pharaoh, and when they were safe across the river, Allah made a promise to Sayyidna Musa (علیہ السلام) and through him to the Bani Isra'il that they should move to the right side of the mount of Tur so that Sayyidna Musa (علیہ السلام) might be given the Torah and so that they might witness him speak with Allah.
وَنَزَّلْنَا عَلَيْكُمُ الْمَنَّ وَالسَّلْوَىٰ (And sent down for you the Mann and Sa1w. - 20:80) This incident occurred when, having crossed the river, they were commanded to enter a sacred city, but they refused and as punishment they were confined to a valley which is known as the valley of Tih (Sinai). They stayed there for forty years and in spite of the punishment which they were undergoing they continued to receive gifts from Allah, and the Mann and Salwa (a special kind of food) was one such gifts which was given to them for their sustenance.
Tazkirul Quran
Maulana Wahiduddin KhanOn ayahs 82–84
After crossing the gulf, Moses and his companions pushed onwards until they reached the Sinai desert. They then went to the foot of Mount Tur, where they were given the code of ethics (shari‘ah) in the form of ten commandments with due solemnity. These people remained in the Sinai Desert for almost forty years. Here, as a special gift of God, they were provided with water and food, manna (mann) and quails (salwa). This arrangement continued till a subsequent generation reached the fertile area of Palestine. Almighty God’s subjects can expect their Creator, as a matter of their right, to provide them with sustenance, whatever the circumstances. That is what they are entitled to. And God has the right to expect that his subjects will never under any circumstances be arrogant or disobedient towards Him. For those who remain grateful to God for His blessings, there shall be further blessings from Him, but for those who become arrogant, there shall be severe and unending punishment.
Uthmani text of the Madinah mushaf (King Fahd Complex). Translation: Saheeh International. Tafsir via Quran.com.