Towards the end of modim in shemonah esrei we say "הטוב כי לא כלו רחמך, המרחם כי לא תמו חסדך.״ Isn't this sentence mixed up, shouldn't it be הטוב כי לא כלו חסדך, המרחם כי לא תמו רחמך. Keeping kindness with kindness and mercy with mercy.
The reason it is stated thusly, is because it is based on Eichah 3:22.
חַֽסְדֵ֤י יְהוָה֙ כִּ֣י לֹא־תָ֔מְנוּ כִּ֥י לֹא־כָל֖וּ רַחֲמָֽיו׃ The kindness of the LORD has not ended, His mercies are not spent. (Sefaria)
The commentators took notice in the change of language that it started with ‘good’ and then ‘mercy’, and ‘mercy’ and then ‘kindness’. And they explained that specifically here there are three levels of good doing, each one on higher than the next. טוב is somebody who does good to someone else that needs it and is deserving. המרחם is one who does good to somebody who is not deserving, but is worthy to have mercy on. חסד is the highest level level of doing good and requires no deserving merit of the receiver because from the standpoint of his actions, he is not worthy to be have mercy on. But it comes from the Giver that desires to do good. This is what we say, that God is the ultimate good because his goodness is not set aside only to those who need it, rather, He shows mercy to somebody who is not even deserving of it. This is the essence of mercy, even those who are not deserving of mercy, in his kindness he shows mercy.
Rabbi Moshe Leib Shachor brought proof to this, that we find [the same pattern of usage] in Tehilim טוב־יהוה לכל ורחמיו על־כל־מעשיו The LORD is good to all, and His mercy is upon all His works. That it says הטבה and then רחמים. As well as חַנּ֣וּן וְרַח֣וּם יְהוָ֑ה אֶ֥רֶךְ אַ֝פַּ֗יִם וּגְדָל־חָֽסֶד׃ The LORD is gracious and compassionate, slow to anger and abounding in kindness. First רחמים and then חסד.