It is as though you were saying, “This man did not deserve that blessing,” and so you begrudge him—precisely the evil that Sūrah al-Falaq warns against.

The essential point is that one should seek refuge with these two sūrahs. Al-Tirmidhī reports that the Prophet—peace and blessings be upon him—used to seek protection from the jinn and from the human evil eye until the revelations Qul aʿūdhu bi rabbil-falaq (Say, “I seek refuge in the Lord of daybreak,” Q 113:1) and Qul aʿūdhu bi rabbi n-nās (Say, “I seek refuge in the Lord of mankind,” Q 114:1) were sent down; thereafter he relied on them and left all other formulas. Allah is the One who grants success.

1018 – Abu Hurayrah (may Allah be pleased with him) reported that the Messenger of Allah—peace and blessings be upon him—said, “Do not turn your homes into graveyards. Satan flees from a house in which Sūrah al-Baqarah is recited.” Narrated by Muslim.

1019 – Ubayy ibn Kaʿb (may Allah be pleased with him) said: The Messenger of Allah—peace and blessings be upon him—asked, “Abu al-Munḏir, do you know which verse of Allah’s Book that you possess is the greatest?” I replied, “Allah—there is no deity except Him, the Ever-Living, the Self-Subsisting.” He then touched my chest and said, “Rejoice in this knowledge, Abu al-Munḏir!” Narrated by Muslim.