What is "k'Kadmoseichem"?
Radak: This is gathering, like "she'Kadmas Shalaf Yavesh" (Tehilim 129:6).
How will Hashem benefit them more than initially?
Radak: I will increase you like you were beforehand, and more.
Malbim: First you will be totally settled, like initially. This was in Bayis Sheni, in the days of the Chashmona'im and Hurdus. Afterwards, in the future, I will benefit you more than before, i.e. when you left Egypt and entered Eretz Yisrael. Then you will know that I am Hashem, and you will recognize My Hashgachah and ability.
What is the grammatical form of "v'Heitivosi"?
Radak #1: It is a composite of Heitavti, like "v'Hitalti Eschem" (Yirmeyah 16:13), and Hetivosi, like "Hetivosa Ki Hayah Im Levavecha" (Melachim I, 8:18).
Radak #2: It is a composite of Yitev and Tov.
What is the grammatical form of "Rishoseichem"?
Radak: The singular is Rishah with a silent Aleph, like Simlah, and the plural is Reshos, like "Semalos" or "Kevasos" (Bereishis 45:22, 21:28), and when they are Samuch, Rishos, like Simlos or "Kivsos ha'Tzon" (ibid. 29).
