In the following verse, 16 names of Vishnu given and mentioned that on which occasion/activity we should chant which name.
Aushadhe Chintayét Vishnum Bhojané cha Janardanam
Shayane Padmanabham cha Vivahé cha Prajapatim
While taking any Medicine one should remember - Lord Vishnu .While Consuming food one should remember – Lord Janardana;While Sleeping one should remember – Lord Padmanabha, During wedding one should remember – lord Prajapati
Yudhe Chakradharam Devam Pravase cha Trivikramam
Naraayanam Tanur-tyagé Sreedharam Priya-sangamé
At war one should remember – Lord Chakradhari, While Traveling one should remember – Lord Trivikrama.Death bed one should remember – Lord Narayana, when meeting your loved ones remember– Lord Sreedhara.
Du-swapne Smara Govindam Sankate Madhusoodanam
Kaanane Naarasimham cha Paavake Jalashaayinam
When having Bad dreams one should remember - Lord Govinda , While in trouble times one should remember– Lord Madhusoodana;While In a forest one should remember - Lord Narasimha, In the midst of fire One should remember - Lord Jalashayina
Jalamadhye Varaham cha Parvate Raghunandanam
Gamane Vamanam chaiva Sarva-kaaryeshu Madhavam
In the middle of water (water activities or travel ) one should remember – Lord Varaha, On a mountain (trekking) one should remember – Lord Raghunandana (Lord Rama). While Travel by foot one should remember – Lord Vamana, when you start any deed remember - Lord Madhava.
Shodashaitaani Naamani Pratarudhaya ya: padeth
Sarva-papa-vinirmukhto Vishnu-loke Maheeyate
One who reads all of these 16 names every morning ,then he will get rid of all the sins and will attain Loka(Moksha) or Heaven.
What I want to know is, why certain names for certain activities. I know reason of some name i.e. Vamana (we should chant while traveling on foot) who use to travel on feet and did cover all lokas with only two steps. So it makes sense that doing dhyanA of Vamana will make traveling on feet benificial. And Varaha (while in water one should do dhayana of Vraha) also makes sense to me because He saved Earth from ocean, he protect Earth from water, hence he is savior if we are in water (my guess). But not all names makes sense to me because I am not aware about those names. So what's the reason behind those names on those conditions/activities?