तपाम्यहमहं वर्षं निगृह्णाम्युत्सृजामि च।अमृतं चैव मृत्युश्च सदसच्चाहमर्जुन॥
tapāmyaham ahaṃ varṣaṃ nigṛhṇāmyutsṛjāmi caamṛtaṃ caiva mṛtyuś ca sad asac cāham arjuna
Word by word
The verse says
I give the heat. I hold back the rain and I send it. I am what does not die, and I am the ending too, Arjuna — what is, and what is not.
In plain words
He takes both sides of every pair, and does not explain himself.
The rain and the withholding of it. What lasts and what stops.
There is no second power in this picture to blame the difficult half on.
Where you've felt this · at work
A farmer's year has a dry spell in it and a week of far too much rain, and both of them arrive out of the same sky. He does not keep two names for the sky. He plans for both, and when he looks up he is looking at one thing.
Going deeper
Refusing to split the world into two powers is one of the oldest decisions this tradition made, and it is expensive.
The cheaper arrangement gives you a good god and a bad one, and every hard thing can be assigned. It is emotionally tidy. This verse closes that option: the heat and the rain, the lasting and the ending, all from one source.
What you get in return is that nothing is outside. A hard year is not evidence that you have fallen into somebody else's territory.
That is cold comfort on a bad day and it is not nothing. Most of the extra suffering people carry comes from the story that their difficulty is a sign of abandonment. This verse takes that story away, and what is left is the difficulty, which is usually more manageable than the difficulty plus the story.