Harm as Contagion

but your father has cheated me, changing my wages time and again. God, however, would not let him do me harm.
Genesis 31:7 (The Contemporary Torah, JPS 2006)

The cheating and wage-changing was bad, but not “harm,” according to Jacob. Harm here is “ra’a,” or “do evil.” It’s the same “ra” from the tree in the garden.

and said, “No, my friends. Don’t do this wicked thing.
Genesis 19:7 (NIV)

“Get out of our way,” they replied. “This fellow came here as a foreigner, and now he wants to play the judge! We’ll treat you worse than them.” They kept bringing pressure on Lot and moved forward to break down the door.
Genesis 19:9 (NIV)

This same “do evil” is first introduced with the men of Sodom and Gomorrah.

I suspect it’s meant to suggest a corrupting kind of harm – the kind that spreads, like abusers creating abusers.

God had to Instruct Jacob

Jacob heard that Laban’s sons were saying, “Jacob has taken everything our father owned and has gained all this wealth from what belonged to our father.” And Jacob noticed that Laban’s attitude toward him was not what it had been.
Then the Lord said to Jacob, “Go back to the land of your fathers and to your relatives, and I will be with you.”
Genesis 31 (NIV)

I am convinced that Jacob is not crafty nor clever nor manipulative.

I think he is slow. Simple. So dim-witted that even after hearing what Laban’s sons were saying and seeing Laban’s attitude, God still had to tell him directly that it was time to leave.

Unconditional Promise

וַיֹּ֤אמֶר יְהֹוָה֙ אֶֽל־יַעֲקֹ֔ב שׁ֛וּב אֶל־אֶ֥רֶץ אֲבוֹתֶ֖יךָ וּלְמוֹלַדְתֶּ֑ךָ וְאֶֽהְיֶ֖ה עִמָּֽךְ׃

Then יהוה said to Jacob, “Return to your ancestors’ land—where you were born—and I will be with you.
Genesis 31:3 (The Contemporary Torah, JPS 2006)

וְהִנֵּ֨ה אָנֹכִ֜י עִמָּ֗ךְ וּשְׁמַרְתִּ֙יךָ֙ בְּכֹ֣ל אֲשֶׁר־תֵּלֵ֔ךְ וַהֲשִׁ֣בֹתִ֔יךָ אֶל־הָאֲדָמָ֖ה הַזֹּ֑את כִּ֚י לֹ֣א אֶֽעֱזׇבְךָ֔ עַ֚ד אֲשֶׁ֣ר אִם־עָשִׂ֔יתִי אֵ֥ת אֲשֶׁר־דִּבַּ֖רְתִּי לָֽךְ׃

Remember, I am with you: I will protect you wherever you go and will bring you back to this land. I will not leave you until I have done what I have promised you.
Genesis 28:15 (The Contemporary Torah, JPS 2006)

The rabbis make it clear, running Genesis 31:3 in parallel to Genesis 28:15: this verse is not conditional. It is not saying “IF you return, THEN I will be be with you.” God has already told Jacob that He *WILL* be with him, and this is a restatement of the Promise God has already made.