Russia's official position is as follows: https://mid.ru/en/foreign_policy/news/2060230/
(Reduced to core points for brevity - see link for full version)

Resolution 2803, as adopted, does not grant the Security Council the requisite prerogatives to maintain peace and security. It contradicts the spirit of genuine peacekeeping and universally recognised international legal decisions, which envisage the creation of an independent and territorially contiguous State of Palestine within the 1967 borders, with East Jerusalem as its capital, coexisting peacefully and securely with Israel.

Russia abstained in the voting, taking into account the stance of the PNA leadership, the position of concerned Arab and Muslim countries in support of the American document, and to avoid a recurrence of violence and military actions in Gaza.**

In short, "a bad peace is better than a good war".

The real reasons for abstaining are always the same: you don't want to anger either side of the debate. Russia supports the two-state solution and wouldn't want to go on record voting in favor of anything else. But they have explicitly berated the US for vetoing "bad peace" resolutions before:

It bears reminding that the war and the suffering of civilians in the enclave could have been halted long ago had Washington not consistently – six times in the past two years – used its veto to block draft resolutions demanding an immediate ceasefire.

Russia's official position is as follows: https://mid.ru/en/foreign_policy/news/2060230/
(Reduced to core points for brevity - see link for full version)

Resolution 2803, as adopted, does not grant the Security Council the requisite prerogatives to maintain peace and security. It contradicts the spirit of genuine peacekeeping and universally recognised international legal decisions, which envisage the creation of an independent and territorially contiguous State of Palestine within the 1967 borders, with East Jerusalem as its capital, coexisting peacefully and securely with Israel.

Russia abstained in the voting, taking into account the stance of the PNA leadership, the position of concerned Arab and Muslim countries in support of the American document, and to avoid a recurrence of violence and military actions in Gaza.

In short, "a bad peace is better than a good war".

The real reasons for abstaining are always the same: you don't want to anger either side of the debate. Russia supports the two-state solution and wouldn't want to go on record voting in favor of anything else. But they have explicitly berated the US for vetoing "bad peace" resolutions before:

It bears reminding that the war and the suffering of civilians in the enclave could have been halted long ago had Washington not consistently – six times in the past two years – used its veto to block draft resolutions demanding an immediate ceasefire.