So he watered [their flocks] for them; then he went back to the shade and said, "My Lord, indeed I am, for whatever good You would send down to me, in need."
Musa, peace be upon him, in Madyan, and how He watered the Flocks of the Two Women
When the man told Musa about how Fir`awn and his chiefs were conspiring against him, he left Egypt on his own. He was not used to being alone, because before that he had been living a life of luxury and ease, in a position of leadership.
فَخَرَجَ مِنْهَا خَآئِفاً يَتَرَقَّبُ
(So he escaped from there, looking about in a state of fear.) meaning, turning around and watching.
قَالَ رَبِّ نَجِّنِى مِنَ الْقَوْمِ الظَّـلِمِينَ
(My Lord! Save me from the people who are wrongdoers!) means, from Fir`awn and his chiefs. It was mentioned that Allah sent to him an angel riding a horse, who showed him the way. And Allah knows best.
فَسَقَىٰ لَهُمَا (So he (Musa) watered (their animal) for their sake - 28:24). That is Sayyidna Musa (علیہ السلام) took pity on the girls and drew out 'water from the well and satiated their goats. It is reported in some narrations that the shepherds after making their cattle drink water used to place a very heavy stone on the mouth of the well to make it unusable, and hence these girls would have only the left over water for their herd. The stone was so heavy that ten men together could move it, but Sayyidna Musa (علیہ السلام) removed it all by himself, and drew water from the well. Perhaps for this reason one of the two girls reported to her father that Sayyidna Musa was very strong. (Qurtubi)
ثُمَّ تَوَلَّىٰ إِلَى الظِّلِّ فَقَالَ رَبِّ إِنِّي لِمَا أَنزَلْتَ إِلَيَّ مِنْ خَيْرٍ فَقِيرٌ (Then he turned to a shade and said, "0 my Lord, I am in need of whatever good you send down to me." - 28:24). Sayyidna Musa (علیہ السلام) did not have any food for the last seven days. He came under the shade of a tree and prayed to Allah describing his condition and need in an exquisite manner. The word Khair is sometimes used for wealth as in the case of إِن تَرَكَ خَيْرًا الْوَصِيَّةُ (he leaves some wealth - 2:180). Sometimes it is used for strength like أَهُمْ خَيْرٌ أَمْ قَوْمُ تُبَّعٍ they better, or the people of Tubba - 44:37) and sometimes for food as in the verse under reference. (Qurtubi)
Tazkirul Quran
Maulana Wahiduddin KhanOn ayahs 24–27
Moses’s departure took him on a journey towards an unknown destination. Moses had the same intense feelings as a believer’s heart experiences under such circumstances. Proceeding on the strength of prayers, he reached Midian after a ten day journey. Following his urge to help the weak, Moses helped the two girls of Madyan. The father of the girls was an elderly gentleman who belonged to the progeny of Abraham through his son Midyaan. Incidentally, Moses also belonged to the progeny of Abraham through his son Isaac (Ishaq), which made them blood relations. At that time, this prayer spontaneously fell from Moses’s lips, ‘Lord, I am truly in need of whatever blessing You may send down for me.’ This prayer shows the condition of a believer in such circumstances. He entrusts all his affairs to the care of God. He has the firm belief that whatever a man receives comes from God, and that whatever is received from God is ‘good’.
Uthmani text of the Madinah mushaf (King Fahd Complex). Translation: Saheeh International. Tafsir via Quran.com.