Believe - Amen
In Genesis 15 it says the “word of YHWH came to Aḇram in a vision, saying, “Do not be afraid, Aḇram. I am your shield, your reward is exceedingly great. And Aḇram said, “Master YHWH, what would You give me, seeing I go childless … And see, the word of YHWH came to him, saying, “.. he who comes from your own body is your heir. And He brought him outside and said, “Look now toward the heavens, and count the stars if you are able to count them.” And He said to him, “So are your seed.”
VERSE 6 : And he believed in YHWH, and He reckoned it to him for righteousness.
The words “And he believed” in Hebrew is AMAN H539 – ‘āman. This is where the word we use(d) to finish prayers usually come from, Amèn. This word in Hebrew is actually a VERB – an action word. It is not just believing like we say in English, a statement. But you SHOW your faith literally by actions – And that is why it was reckoned to Abraham for righteousness. In the following verses, it shows how Abraham asks YHWH what he must do for this promise.
Covenant
In Genesis 15 YHWH makes a COVENANT (H1285 – bᵊrîṯ) with Abraham, with the animals cut in half. In Hebrew you rather say, to “Cut a Covenant” – symbolizing you cannot put back together what is cut in half.
Verse 11 talks about the birds of prey that want to steal the sacrificial animals, i.e. steal the promise, the covenant – and Abraham had to protect it and chase the birds away.
