Genèse 14:19

And he blessed him, and said, Blessed be Abram of the Lord God Most High, who for the righteous possesseth the heavens and the earth.

KONEI (POSSESSOR) OF HEAVEN AND EARTH. Rashi wrote: “Konei is similar to osei (maker);. Psalms 134:3. through His having made them He acquired them as His possession.”
But these are really two different interpretations. and kinyan — making and acquiring — constitute but one interpretation when in fact they are two: konei is similar to osei, and konei is like kinyan (acquisition). Perhaps it is indeed the case that the word kinyan (acquisition) is also used in the case of asiyah (making). Thus you find, For Thou ‘kanita’ (hast made) my reins, repeating the thought [expressed in the second half of the verse], Thou hast knit me together in my mother’s womb. must also refer to “making,” rather than “acquiring.” A similar case is the verse, Is He not ‘konecha’ thy father? Hath He not made thee, and established thee? is used together with asiyah, indicating that they have a similar connotation. Thus the Sacred Language uses kinyan in the case of “making.” Conversely, And the souls which ‘asu’ [literally, they made] in Haran, means “they acquired.” And of that which was our father’s ‘asah’ (hath he made) — [here too it means “hath he acquired.”]
That which Rashi says further — “He acquired them as His possession,” is correct, for whatever belongs to a person is called kinyano (his acquisition). Sheep are called mikneh because they constitute the main wealth of a person. In the language of the Sages: “He who picks up a find for his friend, his friend kanah [has taken title to it];” does not mean that he acquired it from the other since he never picked it up for himself. Instead, it means taking title to it. “watching gives ‘keniya’ (the right of possession) in ownerless property;”, 118a. Here too konah does not mean that he acquired it from another person but that he took title to it. “a man’s yard koneh (obtains title) for him without his knowledge.”, 11a. This too is a similar case. Similarly, the Sages, in all places, use the expression of kinyan for taking possession, meaning that it is his. This was the intention of Onkelos when he translated konei (of heaven and earth) as d’kinyanei, [meaning “Whose possessions are heaven and earth”], and he did not say kanah (who acquired).

ויברכהו ויאמר ברוך אברם לאל עליון, first he blessed on his own behalf. Then he added that Avram was also blessed by the Supreme G’d. He said basically the same as G’d Himself had said to Avram in 12,2.

קונה שמים וארץ, heaven and earth are His, to do with as He pleases. They do not have a will of their own as some scientists believe. G’d alone works His will on them, using them according to His will.

ויברכהו...קונה שמים וארץ, the word קונה here must not be understood in the customary sense of acquiring something from a third party. Malki Tzedek most certainly did not think that “the G’d of heaven and earth” had “bought” his position from some other force. The word is used in the sense of “having created, or having invented.” It was used in this sense by Chavah when she gave birth to Kayin and said קניתי איש את ה', “I have produced, brought forth a man, with G’d,” when she meant that she was now a partner to G’d.” Genesis 4,1)