Psalm 119:36, "Turn my heart toward your statutes, not toward selfish gain," is a plea for a heart that is oriented towards God's law and away from personal greed. Here's a breakdown of its meaning:

"Turn my heart...": This is a prayer, acknowledging that the speaker needs divine assistance. The heart, in biblical terms, represents the core of a person – their thoughts, desires, will, and affections. The speaker recognizes they can't simply will themselves to change; they need God's intervention.

"...toward your statutes...": Statutes are God's specific rules, laws, and commands found in the Bible. This means the speaker desires to focus their thoughts, desires, and actions on following God's will. They want their heart (their entire being) to be drawn toward understanding, obeying, and delighting in God's word.

"...not toward selfish gain...": Selfish gain refers to the pursuit of personal wealth, power, pleasure, or any advantage sought for oneself, often at the expense of others or in defiance of God's will. This highlights the danger of greed and materialism. The speaker recognizes that a heart focused on selfish gain will inevitably lead away from God's path.

In essence, the verse is a prayer for:

Prioritization of God: It asks God to help the speaker prioritize His law and will above all other things.
Protection from Greed: It seeks protection from the corrupting influence of selfishness and the pursuit of worldly possessions or advantages.
Alignment with God's Will: It expresses a desire to have one's heart and desires aligned with God's purposes, rather than personal ambition.
Spiritual Focus: It is a plea for a focused, unwavering commitment to God's principles.

The verse is a relevant prayer for anyone who struggles with materialism, ambition, or the temptation to prioritize personal desires over God's will. It's a reminder that true fulfillment is found in following God's path, not in pursuing selfish gain.