This question pertains to Psalm 113. In verses 6,7,8,and 9 the ending hiriq yud seems to be used to indicate third person singular verbs rather than first person singular. Is this true? It is the meaning used in all translations I have seen. Is this a common use of a hiriq yud suffix in the Psalms or other places in the Tanach?
It appears in verse 5, too, and the commentaries there note it. Rashi says the final yod is extra, seemingly implying that it has no meaning at all. Thus, it doesn't indicate any particular person or number, unlike what you thought. M'tzudas Tziyon and Radak (the latter to Isaiah 22:16) seem to agree with that. Malbim says it implies constancy of the action mentioned, so that (in verse 5) it means not just "who raises" but something like "who always raises", and likewise in the subsequent verses.
Malbim says this form appears a few other places in Tanach, including Deuteronomy 33:6 and Isaiah 22:16. Rasak to Isaiah 22:16 also points to Psalms 123:1. Rashbam to Exodus 15:2 points also to that verse and to Lamentations 1:1, Jeremiah 49:16. My thanks to Sefaria's tools for connecting me to these commentaries.
Gesenius (90k–m) notes that this yod appears most often on a noun in the construct state or, similarly, a participle closely connected to the following word, and thinks that it's to emphasize the connection. Where it's not on a word thus closely connected to the following word — as in your examples from Psalms 113 — he thinks the yod "merely serves as an ornamental device of poetic style". He lists a number of additional examples, q.v.