Who are "Shurai"?
Rashi: They are those who look at me, like "Shorerai" (5:9). Radak - they are enemies who look for evil, like "Ashurenu v'Lo Karov" (Bamidbar 24:17). Shurai is To'ar (kind of person); it has a Shuruk, like "Nechaletz Chushim" (Bamidbar 32:17).
What did he [see and] hear?
Rashi: I heard in back of the curtain 1 that they will not succeed to eradicate us.
Radak: I saw and heard what I wanted. The same applies to "uv'Oyvai Ra'asah Eini" (54:9).
Malbim: I saw the people who look at me when evildoers rose against me, and I heard what they say (refer to 92:13:1:4).
There is a curtain above, in back of which decrees are heard (Brachos 18b, Yuma 77a, Chagigah 16a-b...) (PF)