What is the ruling on uttering the Name of Majesty "Allah" by omitting the letter "Hāʾ" (هـ), such as saying "al-Lā" or "in shāʾal-Lā"?

It is permissible to omit the letter 'ha' (ه) from the word 'Allah' (الله) in normal speech, as long as it does not change the meaning. However, it is more proper to mention it in its complete form. But omitting it is not permissible in verbal acts of worship, such as:

The Adhan (call to prayer): Some scholars hold that it is invalid if the 'ha' is omitted.

Takbirat al-Ihram (the opening 'Allahu Akbar' in prayer): Some scholars hold that the prayer is invalid if the 'ha' is omitted.

Scholars have differed regarding the validity of an oath and the permissibility of slaughtered meat when the 'ha' is omitted, so it is safer not to omit it.