We see from last week’s parsha that Avraham has picked up and headed for Canaan, even before receiving a commandment from God.
This parasha is full of messages about belief, trust in God, and Aliyah - in the midst of Avraham's immigration which is full of question marks.
There is a commandment but also a pull toward Eretz Yisrael. For Avraham and for contemporary olim (immigrants), there is no initial promise that everything is going to work out - we have to wait for the next part of the parasha where God will give us the promise. The idea of hope during a time of many unknowns also relates to Rosh Hodesh, a time of optimism and looking forward to the middle of the month when the moon is in full view, and when many of our festivals are celebrated, symbolizing God's manifestation to Israel after periods of seeming obscurity - periods to cultivate optimism.