Albert Barnes Commentary Matthew 8:10

"And when Jesus heard it, he marvelled, and said to them that followed, Verily I say unto you, I have not found so great faith, no, not in Israel." — Matthew 8:10 (ASV)

I have not found so great faith. The word faith here means confidence, or belief that Christ had power to heal his servant. It does not of necessity imply that he had saving faith, though from the connection and the spirit shown, it seems probable that he had. If this was so, then he was the first Gentile convert to Christianity and was a very early illustration of what was more clearly revealed afterward: that the Gentiles were to be brought to the knowledge of the truth.

Jesus—marveled. Or wondered at his faith; or deemed it remarkable.

Not in Israel. Israel was a name given to Jacob (Genesis 32:28–29), because, as a prince, he had power with God, and also because he persevered in wrestling with the angel that met him and obtained the blessing. The name is derived from two Hebrew words, signifying Prince and God.

He was one of the patriarchs, an ancestor of the Jewish nation; and the names Israel and Israelites were given to them, much as the name Romans was in honor of Romulus, and the name Americans after Americus Vespuccius.

The name Israel was given to the whole nation until the time of Jeroboam, when only the ten tribes that revolted received the name, probably because they were a majority of the nation. After the Babylonian captivity, it was given to all the Jews indiscriminately (Acts 7:42; Hebrews 8:8; Mark 15:32).

In this context, Not in Israel means, "I have not found such an instance of confidence among the Jews."