Translation of the verse 20 from Surah Ash-Shu‘ara’ : Number of verses 227 - - page 368 - Part 19.
Musa (Moses) said: "I did it then, when I was an ignorant (as regards my Lord and His Message).
[Moses] said, "I did it, then, while I was of those astray.
(26:20) Moses answered, "I did it inadvertently; *16
*16) The word dalalat dces not always mean "straying away", but it is also used in the sense of ignorance, folly, error, forgetfulness, inadvertence, etc. As mentioned in Surah Al-Qasas, Prophet Moses had only given a blow to the Egyptian (Copt) when he saw him treating an Israelite cruelly. A blow dces not cause death, nor is it given with the intention of causing death. It was only an accident that the Egyptian died. As such, it was not a case of deliberate murder but of accidental murder. A murder was committed but not intentionally, nor was any weapon used, which is usually employed for murder, or which can cause murder.
Source : Ash-Shu‘ara’ Verse 20: [Moses] said, "I did it, then, while I was of those astray.