What is the ruling on uttering phrases such as: "By God's protection (Dakhil Allah)", "By the Prophet's protection (Dakhil al-Nabi)", and "cursing the sky (La'n al-Sama')"?

A Muslim should avoid ambiguous words or those that carry an unseemly meaning. The phrase "Dakhil Allah" (دخيل الله) means seeking refuge with Allah, which is a correct meaning, and it may be used with other meanings that are not objectionable. As for "Dakhil Al-Nabi" (دخيل النبي), its origin means seeking succor from the Prophet, which is false. However, many people in the Levant use it to mean "for the sake of the Prophet" rather than seeking succor, even though it should be avoided. The saying "Yal'an Samak" (يلعن سماك) is used for cursing and swearing, and it may mean cursing the sky, which is forbidden because the sky is not deserving of curses, and cursing is prohibited.