Rashi: Lavan ran when he heard who had arrived. He figured that if the family's servant had arrived with ten camels laden with 'goodies,' imagine what the master must have brought with him! So he ran out to see what was in it for him. ¹

Seforno: He ran when he heard how Yaakov had removed the stone from the well single-handed.

Targum Yonasan: He ran because he was intrigued by his nephew's strength and piety, and by all that happened to him - the episode of the Berachos, the revelation in Beis-El, how he had rolled the stone off the well and how the well began to flow and rose to meet him.

Tosfos ha'Shalem (6): Lavan wanted to steal from him.

Rashi (from Bereishis Rabah 70:13): When he saw no camels, he thought that perhaps he had brought gold coins with him, which were hidden somewhere on his body, so he embraced him; ¹ when he found nothing, he figured that he must have hidden some jewels in his mouth, ² so he kissed him.

Ha'amek Davar: One who comes from afar, first he stretches out his hand to embrace, and afterwards he kisses. Below, Yaakov was already close to Efrayim and Menasheh.

Rashi: He told him that he was running away from his brother and related what had happened on the way - to explain why he came empty-handed. ¹

Rashbam: That his parents had sent him, to be with his family.

Ha'amek Davar: He informed him that he came to escape his brother, according to his mother's instructions. Seforno - he also said that he did not come for income.

Bechor Shor: He told him about getting the Berachos and Bechorah, so Lavan will want to give his daughter to him.

Ohr ha'Chayim: He told him about his Chochmah to get the Bechorah and Berachos, so Lavan will know that he is crafty to get what he needs, and he told him about the rock, so he will not know that he is very strong, and about watering the flock, to teach that Yaakov endears him and will act straight with him.

Ohr ha'Chayim: Rachel did not tell Lavan that Yaakov said that he is his brother [in deceit], only that he is Ben Rivkah - a Tzadik ben Tzadekes.

Ohr ha'Chayim: He thought that perhaps Yaakov's property will come later. He granted him entry until his property would arrive.

Malbim: Hagadah is telling what is relevant to the listener, and he needs to know it. Sipur is telling what is not relevant to the listener. Lavan had no love of relatives in his heart.

Ha'amek Davar: Rachel was not aroused through hearing his name, only that he was Ben Rivkah. Lavan was aroused; he had already heard about Yaakov. Whoever learns Torah covertly, the Torah announces about him externally (Mo'ed Katan 16b).

Ha'amek Davar (here and to 33:4): "Va'Yechabek Lo va'Yenashek Lo" implies that they hugged and kissed each other. Yaakov did not hug and kiss Esav, whom he called 'my master' (32:4).