Imam al-Baqir (PBUH): “The companion of this matter will go into occultation in some of these passes” and he pointed out with his hand to the direction of Thee-Towa. Then he said: “Until BEFORE HE COMES OUT, the Mawla who was with him will come forth until he meets some of his companions and ask: ‘How many of you are there?’ They will reply: ‘We are forty people.’ Then he will ask: ‘What will you do if you see your Companion (the Companion of the Matter (PBUH))’ They will reply: ‘By Allah, if he goes from here and takes refuge at any mountain, we will also be with him.’ Then he will come to them and say: ‘Point to ten of your leaders or the best of you,’ then they point to them for him, so he takes them and brings them to their Companion (Imam Mahdi). He will promise them the coming night (or he meets them the coming night)..” Ghaibat Al-Noa’mani, P. 187, Tafsir Al-Ayashy, V. 2, P. 56, Bihar Al-Anwar, V. 52, P. 341, Mu’jam Ahadith Al-Imam Al-Mahdi, V. 5, P. 2.
عن الباقر (ع): (يكون لصاحب هذا الأمر غيبة في بعض هذه الشعاب – وأومأ بيده إلى ناحية ذي طوى – حتى إذا كان قبل خروجه أتى المولى الذي كان معه حتى يلقى بعض أصحابه، فيقول: كم أنتم هاهنا ؟ فيقولون: نحو من أربعين رجلاً، فيقول: كيف أنتم لو رأيتم صاحبكم ؟ فيقولون: والله لو ناوى بنا الجبال لناويناها معه، ثم يأتيهم من القابلة ويقول: أشيروا إلى رؤسائكم أو خياركم عشرة، فيشيرون له إليهم، فينطلق بهم حتى يلقوا صاحبهم، ويعدهم الليلة التي تليها) ().
Some Ansars showed the below hadith which is wrong translation:
said: “Abu Muhammad has commanded me by it.” So he said: “Now you have come with it, and none other could have brought this forth except someone from this House.” Then he prepared fire and burnt all that which he had written” – Manaqib Ale Abi Talib: volume 3, page 525, Bihar Al Anwar: volume 10, page 392.
And this indicates that there is an absence of clearness/preciseness of its meaning to them in a way that does not have confusion/ambiguity in it. Therefore, it is not clear/precise in meaning, but rather, it is allegorical (with hidden meaning). Thus, is it possible that you have fallen into wrong understanding of this narration? And do you not know that there are clear/precise narrations indicating the existence of an ambassador before the rising of the Qa’im? And they are considerably great [in number], and this example is from them, only to remember, from al-Baqir (PBUH): “Imam Qa’im (a.s.) will go into occultation in some of these passes” and he pointed out with his hand to the direction of Zeetawa. Then he said: “When two days remain from his rising, one of his special servants would come to his particular companions and ask: ‘How many of you are there?’ He would reply: ‘We are forty people.’ Then he will ask: ‘What will you do if you see your Companion (the Companion of the Matter (PBUH))’ They will reply: ‘By Allah, if he goes from here and takes refuge at any mountain, we would also be with him.’ Then he will come to them and say: ‘Point to ten of your leaders or the best of you,’ then they point to them for him, so he [takes them] and brings them to their Companion, and he shall promise them the coming night.” 
First of in the hadith that imam a.s put in his book, there is no “when 2 days remain from his rising” written as you may see above (both in english and arabic version of the books of Imam a.s)
Also, from the context of the hadith it could be understood that when the imam a.s. says “until before his emergence” could mean until before his emergence from the occultation, meaning until before he exits from the occultation because the hadith starts with the occultation, then it says, so it could mean “so before he comes out [from the occultation], the mawla with him will come forth etc until the end of the hadith. Actually so another translation can be “before he comes out” instead of “before his emergence.