[SKAzini]

pawn Код:

new MessageStatus[MAX_PLAYERS];
new SpawnMessageTimer[MAX_PLAYERS];

forward SpawnMessage(playerid);

public OnPlayerSpawn(playerid)
{
    MessageStatus[playerid] = 0;
    SendClientMessage(playerid, xxxxxxxxxx, "blablabla. 0");
    MessageStatus[playerid]++;
    SpawnMessageTimer[playerid] = SetTimerEx("SpawnMessage", 5000, true, "i", playerid);
    return 1;
}

public SpawnMessage(playerid)
{
    switch(MessageStatus[playerid])
    {
        case 1: SendClientMessage(playerid, xxxxxxxxxx, "blablabla. 1");
        case 2: SendClientMessage(playerid, xxxxxxxxxx, "blablabla. 2");
        case 3: SendClientMessage(playerid, xxxxxxxxxx, "blablabla. 3");
        default: KillTimer(SpawnMessageTimer[playerid]);
    }
    MessageStatus[playerid] ++;
}

Untested.

5 seconds (5000ms) between every message.
4 messages.