The expression “post-haste” was something I once heard from a teacher and it followed a request to go to some office to get something. “And do it post-haste.” I thought about the meaning of that expression then about as often as I did about any expression — not at all. But, that expression has a history:
On the envelope of a letter a writer would write “haste, post, haste” to signal to the post carrier that he or she wanted this letter to get to its destination soon and very soon.

The psalmist, in 119:58-60, declares to God that he is intent on imploring God from the depth of his heart (v. 58), he is resolute in his commitment to do God’s decrees, and he has “hurried and not delayed” to keep God’s commandments — posthaste, we might say, he has committed to do what God says.
I’m guessing you are as busy this time of year as we are. The psalmist captures our hurrying about with a word: Are we “hurrying” (posthaste) to do God’s will? When confronted with two options, are we in a hurry to do what God wants or in a hurry to do what we want?