Al-Qasas 28:18 فاصبح في المدينة خايفا يترقب فاذا الذي استنصره بالامس يستصرخه قال له موسى انك لغوي مبين ١٨

How the Secret of this Killing became known

Allah tells us that when Musa killed that Coptic,

(he became afraid in the city) meaning, of the consequences of his action,

(looking about) means, turning around and watching out, waiting for the consequences of his action