1)
Did he inherit the Edos?!
1.
Radak: They are like an inheritance to me. I am established in them, like a person who is always established in his inheritance. I will not leave and cease to hold them for [even] a short time.
2.
Malbim: Edos are tales in the Torah that testify about Hashem's ways; Pikudim sprout from them. They are an inheritance to me, for they became a permanent Kinyan in my Nefesh.
2)
How are they "Sason Libi"?
1.
Radak: This is like "Pekudei Hashem Yesharim Mesamchei Lev"; refer to 19:9:3:1.
2.
Malbim: I rejoice when I see Hashem's ways in the Edos, and His straightness, goodness, Hashgachah and mercy on those who fear Him.