Abbas - Tanwîr al-Miqbâs min Tafsîr Ibn ‘Abbâs
(And morning found him in the city, fearing) because of killing the Copt, (vigilant) anticipating arrest, (when behold! he who had appealed to him the day before) to help against the Copt (cried out to him for help) against another Copt. (Moses said unto him) to the Israelite: (Lo! thou art indeed a mere hothead) you are a quarrelsome person, and proceeded to help him.
In the morning he was in the city, fearful, vigilant, waiting to see what would happen to him [in reaction] from the side of the slain man; — when behold, the one who had sought his help the day before cried out to him for help [again], asking for his help against another Egyptian. Moses said to him, ‘Clearly you are a trouble-maker!’, whose trouble-making is evident, judging by what you did yesterday and today.
(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 to befall him. He went out and about, and saw the man who sought his help the day before, fighting with another Coptic. When Musa passed by him, he called for his help again, against this other Coptic. Musa said to him:
إِنَّكَ لَغَوِىٌّ مُّبِينٌ
(Verily, you are a plain misleader!) meaning, `you obviously lead people astray and are very evil.' Then Musa intended to attack that Coptic, but the Israelite -- because of his own cowardice and weakness -- thought that Musa wanted to hit him because of what he had said, so he said, in self-defence --
(O Musa! Is it your intention to kill me as you killed a man yesterday) Nobody except him and Musa, peace be upon him, knew about it, but when the other Coptic heard this, he took the news to Fir`awn's gate and told him about it. So Fir`awn came to know of it, and he became very angry and resolved to kill Musa, so he sent people after him to bring him to him.
Maududi - Sayyid Abul Ala Maududi - Tafhim al-Qur'an
That is, "You seem to be a quarrelsome man:you have daily a new quarrel with one or the other person."
Here, the Biblical version is different from the Qur'anic. The Bible says that the fight on the next day was between two Israelites, but according to the Qur'an this fight also was between an Israelite and an Egyptian. This second version seems to be credible, for the manner in which the secret of the murder of the first day became known, as is being mentioned below, could be possible only if a member of the Coptic community had come to know of the matter. An Israelite's knowledge of it could not be so treacherous: he could not have gone to inform the Pharaonic government of such a heinous crime committed by the prince, who was a great supporter of his own community.
The one who cried out was the same Israelite whom the Prophet Moses wanted to help against the enemy. When after scolding and rebuking him, he turned to assault the Egyptian, the Israelite thought that Moses was going to strike him; therefore, he raised a hue and cry and disclosed the secret of the previous day's murder by this own folly.
This happened when in the second day's fight, the secret of the murder became known and the Egyptian informed the authorities about the case accordingly.