Tafsir of Ta-Ha 20:67

Al-Ijas means concealment, and khifah means fear. Its origin is khawfah; the waw was changed into a ya because of the kasra of the letter preceding it. Ibn Atiyyah said: It is possible that it is khawfah (with a fatha on the kha), where the waw was changed into a ya, and then the kha was given a kasra for the sake of harmony; however, the former is more appropriate.

The tanwin (in khifatan) is for belittlement, meaning he concealed within himself a slight fear due to the suddenness of the event, in accordance with the demands of human nature upon seeing a terrifying matter; this is the statement of Al-Hasan.

Muqatil said: Peace be upon him feared that the people might encounter doubt or suspicion regarding the miracle of the staff when they saw their own staffs, and he concealed his fear of that so that their resolve would not be strengthened if it became apparent to them, which would lead to them not following him.

It is said that the tanwin is for magnification, meaning he concealed within himself a great fear. Some have said that the linguistic form—being a fa'lah—indicates a state and a persistent condition, and thus it denotes that; for this reason, it was chosen over khawf (fear) in the verse: "And the thunder exalts [Allah] with praise of Him and the angels [as well] from His khifah" (13:13). The word awjas does not contradict this, though some say it does.

The first interpretation (belittlement) is more suitable for the state of Musa (peace be upon him) if his fear was of the nature mentioned by Al-Hasan. The second (magnification) is more suitable for his state if his fear was of the nature mentioned by Muqatil. It is also said that it is more suitable in light of the description of the magic as "great" in the verse: "And they came with a great magic" (7:116). Some have supported the view that the tanwin is for magnification by pointing to the fact that Musa expressed it rather than concealing it—so contemplate this.

It is also said that he (peace be upon him) heard when they said: "Either you throw..."—O allies of Allah—so he feared on account of that, knowing that the allies of Allah are not defeated. This is hardly sound, and the noble structure of the verse rejects it.

The delay of the agent (Musa) is to observe the rhyme scheme.