sentence1: Now the promises were spoken to Abraham and to his offspring. He doesn’t say, “To descendants”, as of many, but as of one, “To your offspring”, which is Christ.
sentence2: Τῷ δὲ Ἀβραὰμ ἐρρήθησαν αἱ ἐπαγγελίαι, καὶ τῷ σπέρματι αὐτοῦ. Οὐ λέγει, Καὶ τοῖς σπέρμασιν, ὡς ἐπὶ πολλῶν, ἀλλ᾽ ὡς ἐφ᾽ ἑνός, Καὶ τῷ σπέρματί σου, ὅς ἐστι Χριστός.