ولما ورد ماء مدين
And when he arrived at the water (a well) of Madyan,
means, when he reached Madyan and went to drink from its water, for it had a well where shepherds used to water their flocks,
وجد عليه أمة من الناس يسقون ووجد من دونهم امرأتين تذودان
he found there a group of men watering, and besides them he found two women who were keeping back.
means, they were stopping their sheep from drinking with the sheep of those shepherds, lest some harm come to them. When Musa, peace be upon him, saw them, he felt sorry for them and took pity on them.
قال ما خطبكما
He said: "What is the matter with you?''
meaning, `why do you not water your flocks with these people?'
قالتا ﻻ نسقي حتى يصدر الرعاء
They said: "We cannot water until the shepherds take...''
meaning, `we cannot water our flocks until they finish.'
وأبونا شيخ كبير
And our father is a very old man.
means, `this is what has driven us to what you see.'