Numbers 24:2

וישא בלעם את עיניו AND BALAAM LIFTED UP HIS EYES — he wished to cast the evil eye upon them. Thus you have his three characteristics — an evil eye mentioned here, and pride and greed which have been mentioned above (see Rashi on Numbers 22:13 and 18). שכן לשבטיו DWELLING ACCORDING TO HIS TRIBES — He saw each tribe dwelling by itself not intermingled one with another; he saw that the entrances of their tents were not exactly facing each other so that one could not peer into the other's tent (Bava Batra 60a). ותהי עליו רוח אלהים AND THE SPIRIT OF GOD WAS UPON HIM — Then he made up his mind not to curse them (i.e. he decided to comply with the will of God, רוח אלהים).

וַיִּשָּׂ֨א בִלְעָ֜ם אֶת־עֵינָ֗יו וַיַּרְא֙ אֶת־יִשְׂרָאֵ֔ל שֹׁכֵ֖ן לִשְׁבָטָ֑יו וַתְּהִ֥י עָלָ֖יו ר֥וּחַ אֱלֹהִֽים׃

And Bil῾am lifted up his eyes, and he saw Yisra᾽el abiding according to their tribes; and the spirit of God came upon him.