You claim the passage is metaphorical without evidence and then question my research?
BGT Genesis 13:15 ὅτι πᾶσαν τὴν γῆν ἣν σὺ ὁρᾷς σοὶ δώσω αὐτὴν καὶ τῷ σπέρματί σου ἕως τοῦ αἰῶνος (Gen. 13:15 BGT)
So, where is your explanation of your "research"? All that you have done is quoted the BGT/LXX which is the Greek translation of the original Hebrew text.
The BGT/LXX is just as flawed as our English translations. Now unless you provide your understanding of what the Greek text is actually saying in English, then you are an empty jar with no substance to edify those who would read your posts.
I too can simply cut and paste the BGT/LXX as you have done, but unless you know that the BGT/LXX translation is an accurate rendition of the original Hebrew text, you are only repeating the fallible understanding of the Jewish scholars involved in the generation of the BGT/LXX. The same is also true for our English translations.
Just to prove my point, I too, can post the LXX version of Genesis 13:14-18 and it is pointless for most people if I do not explain what all of the Greek words mean.
Genesis 13:14-18: - God Renews the Promise to Abram
14 Ὁ δὲ θεὸς εἶπεν τῷ Ἀβρὰμ μετὰ τὸ διαχωρισθῆναι τὸν Λὼτ ἀπ᾽ αὐτοῦ Ἀνάβλεψον τοῖς ὀφθαλμοῖς σου καὶ ἴδε ἀπὸ τοῦ τόπου οὗ νῦν σὺ εἶ πρὸς βορρᾶν καὶ λίβα καὶ ἀνατολὰς καὶ θάλασσαν· 15 ὅτι πᾶσαν τὴν γῆν ἣν σὺ ὁρᾷς, σοὶ δώσω αὐτὴν καὶ τῷ σπέρματί σου ἕως τοῦ αἰῶνος. 16 καὶ ποιήσω τὸ σπέρμα σου ὡς τὴν ἄμμον τῆς γῆς· εἰ δύναταί τις ἐξαριθμῆσαι τὴν ἄμμον τῆς γῆς, καὶ τὸ σπέρμα σου ἀριθμηθήσεται. 17 ἀναστὰς διόδευσον τὴν γῆν εἴς τε τὸ μῆκος αὐτῆς καὶ εἰς τὸ πλάτος· ὅτι σοὶ δώσω αὐτὴν καὶ τῷ σπέρματί σου εἰς τὸν αἰῶνα. 18 καὶ ἀποσκηνώσας Ἀβρὰμ ἐλθὼν κατῴκησεν παρὰ τὴν δρῦν τὴν Μαμβρήν, ἣ ἦν ἐν Χεβρών· καὶ ᾠκοδόμησεν ἐκεῖ θυσιαστήριον Κυρίῳ.
14 Ὁ δὲ θεὸς εἶπεν τῷ Ἀβρὰμ μετὰ τὸ διαχωρισθῆναι τὸν Λὼτ ἀπ᾽ αὐτοῦ Ἀνάβλεψον τοῖς ὀφθαλμοῖς σου καὶ ἴδε ἀπὸ τοῦ τόπου οὗ νῦν σὺ εἶ πρὸς βορρᾶν καὶ λίβα καὶ ἀνατολὰς καὶ θάλασσαν· 15 ὅτι πᾶσαν τὴν γῆν ἣν σὺ ὁρᾷς, σοὶ δώσω αὐτὴν καὶ τῷ σπέρματί σου ἕως τοῦ αἰῶνος. 16 καὶ ποιήσω τὸ σπέρμα σου ὡς τὴν ἄμμον τῆς γῆς· εἰ δύναταί τις ἐξαριθμῆσαι τὴν ἄμμον τῆς γῆς, καὶ τὸ σπέρμα σου ἀριθμηθήσεται. 17 ἀναστὰς διόδευσον τὴν γῆν εἴς τε τὸ μῆκος αὐτῆς καὶ εἰς τὸ πλάτος· ὅτι σοὶ δώσω αὐτὴν καὶ τῷ σπέρματί σου εἰς τὸν αἰῶνα. 18 καὶ ἀποσκηνώσας Ἀβρὰμ ἐλθὼν κατῴκησεν παρὰ τὴν δρῦν τὴν Μαμβρήν, ἣ ἦν ἐν Χεβρών· καὶ ᾠκοδόμησεν ἐκεῖ θυσιαστήριον Κυρίῳ.
Shalom