"In one explanation, the Midrash taught that just as oil floats to the top even after it has been mixed with every kind of liquid, so Israel, as long as it performs the will of God, will be set on high by God, as it says in 

Rabbi Joshua of Siknin in the name of Rabbi Levi interpreted to convey God's message that if people will heed God's commandments, God will heed their prayers.Rav's disciples told Rabbi Abba that Rav interpreted the words of "Blessed shall you be in the city," to mean that your house would be near a synagogue.